Snailbot Crawls into Action

Snailbot crawls into action, as described in news@nature, 13 December 2005. A team of engineers at the Massachusetts Institute of Technology (MIT) have built a "mechanical mollusc" that can climb wall and crawl along ceilings in a similar fashion to a snail. Snails move by contracting the muscle in their foot over a bed of slime that attaches them to the surface and prevents them from going backwards. The muscle contraction starts at the rear of the foot and moves forward until it lifts the front end off the surface. The snail then stretches out to its full length, reattaches to the surface and pulls the rest of its body forward.

The MIT engineers designed a mathematic model of this movement and built a robot with five moveable segments to test the model. As the robot did not produce its own layer of slime the engineers ran their robot over a platform covered with a clear sticky gel made from Laponite (a type of clay). The researchers admit "that snail locomotion is slow, slimy and inefficient" so there may not be a great demand for a snailbot. However, snails can crawl over just about any surface, which means they can move about in many different environments – a useful property for a robot.

Editorial Comment: Whether the snailbot becomes a useful device or remains an academic engineering oddity, it didn’t come about by chance random processes. The MIT engineers first had to study a living snail, invent a mathematical model and built a device that could only carry out one function. By using their minds clever scientists built a far inferior mechanism compared with a real snail. Therefore, they have no excuse for not recognising that the real snail was created by a far cleverer scientist. (Ref. design, biomimmetics, robotics)